Rotary toothbrush with lip guard



Dec. 5, 4195() D. P. GRovl-:R 2,533,106

ROTARY TOOTHBRUSH WITH LIP GUARD Filed Aug. 17, 194e IN VEN TOR. BUMP'foaf, BY

thereof Patented Dec. 5, 1,950

UNITED STATES PATENT oFFlcE.

ROTARY TOOTHBRUSH WITH LIP GUARD Donald P. Grover, Chicago, Ill.Application August 17, 1946, Serial No. 691,273

3 Claims.

Y This invention relates in general to rotary toothbrushes and inparticular to a type of rotary toothbrush adapted for personal use, asdistinguished from those commonly used by dentists.

Various forms of electrically driven rotary toothbrushes have beendeveloped heretofore, but have found very little favor with the publicin general. One of the disadvantages of the early type of rotarytoothbrush was the absence oi any shield partially surrounding the brushelement, thus causing some of the toothpaste on the brush to be thrownoff and splattered about during the rotation of the brush and permittingthe brush to contact the soft inner portions of the mouth causingirritation thereof.

A later development introduced a shield which extended lengthwise of andpartially surrounded the rotating brush element to prevent suchsplattering and mouth irritation. However, actual usage of this type ofbrush proved unsatisfactory because of the tendency of the lip of theuser to be drawn inwardly against the bristles or" the brush and betweenthe bristles and the edge of the shield when the brush was placedagainst the teeth.

I have been able to overcome the disadvantages of these earlier types ofrotary toothbrushes in my present invention, the principal object ofwhich is to provide an electrically driven rotary toothbrush havingnovel guard means to prevent the lip of the user from being pulled ordrawn inwardly against the bristles of the brush element during rotationthereof.

Another object of the invention is to provide a rotary toothbrush havinga plurality of spaced guards along the length of the brush element andextending between the bristles thereon whereby the lip of the user isprevented from being pulled or drawn inwardly against the brush duringro tation thereof.

A further object is to provide a rotary toothbrush having a shieldextending lengthwise of andr partially surrounding the brush element,wherein a plurality of thin guard members are spaced along the length ofthe shield andextend inwardly between bristles of the Ybrush elementfrom the upper edge o the shield to prevent the lip of a user from beingdrawn inwardly between the shield and brush element during rotationStill another object is to provide a rotary toothbrush having a shieldextending longitudinally of and partially surrounding the brush element,wherein various types or forms oi guard members such as teeth,partitions, prongs or the like may be spaced along the length of theshield and extend inwardly between the bristles of the brush elementfrom either or both of the edges of the shield, whereby the lip of theuser will be prevented from being drawn inwardly between the shield andbrush element while it is rotating and in use. v

Other objects and advantages oi the invention will become apparent upona reading of the following description taken in conjunction with theaccompanying drawing in which:

Fig. 1 is a longitudinal section through the handle and brush element ofthe present invention;

Fig. 2 is a vertical longitudinal section taken substantially along theplane of line 2-2 of Fig. 1;

Fig. V3 is a fragmentary vertical section taken substantially along theplane of line 3--3 oi' Fig. 1;

Fig. 4 is a vertical transverse section taken substantially along theplane of line t-e of Fig. 1;

Fig. 5 is a vertical transverse section taken substantially along theplane of line of Fig. '1;

Fig. 6 is a vertical transverse section taken substantially along theplane of line 6-6 of Fig. 1;

Fig. '7 is a perspective View of the handle and guard means with thebrush element removed therefrom;

Fig. 8 is a fragmentary perspective view of a modiiied form of shieldand guard means;

Fig. 9 is a vertical transverse section through the shield of Fig. 8showing one of the guard ele ments in elevation; and

Fig. 10 is a vertical transverse section through the shield showing astill further modiiied form of guard means.

Briefly described, the invention herein consists primarily in theprovision of guard means against which the lip of the user of the rotarytoothbrush will ordinarily bear during the use thereof to guide ordirect the lip to the outer side of the shield and thus prevent the lipfrom being drawn inwardly between the brush element and the shield. Whenthe rotary brush is in use and placed against the teeth, the brushelement is usually designed to rotate in a manner to brush the teethaway from the gums, which is considered by dentists as the proper way tobrush teeth. In actual practice where no lip guards are present, it hasbeen found that brushes of this character disclosed in the prior arthave a tendency to pull the lip inwardly against the bristles of thebrush, and if a shield is present, the tendency is to pullthe lipbetween the brush and the edge of the shield; Serious injury to the lipmay not necessarily result, but such an experience is decidedlyunsatisfactory and unpleasant, discourages further use of the device bycausing rawness and bleeding of the lip and has been considered theprincipal reason for the lack of commercial success of earlier rotarytoothbrushes. It will be obvious that numerous specific forms of guardmeans may be designed to accomplish the main purpose of this inventionand several of these forms have been disclosed herein.

Referring now more particularly to the drawing, the main body or handleportion I may assume any desired shape and size, but preferably itshould be of a size convenient to beheld in the hand and should beformed of a plastic or other similar non-conducting material. Broadlyspeaking, the handle portion may embody its own electric motor, or itmay be driven from an external source. The present form of the inventionas disclosed herein contemplates the use of a ,rotatable shaft withinthe handle which may be easily connected to a ilexible'shaft forpurposes f driving the brush. In the specific form shown, the-handleportion I is provided with a longitudinal opening 2 adapted to receive arotatable shaft 3. One end of the opening is provided with a bearing 4and the opposite end has a similar bearing 5 to thereby rotatablysupport the shaft 3; at eachend thereof. The rear or outer end of theshaft 3 may be provided with a transverse rib 6 adapted to be receivedin a suitable opening or socket in a exible shaft (not shown) forpurposes of driving the brush. The rear of the handle may also beprovided with radially extending ribs l' to securely hold the end of`the flexible shaft in place.

The rear endl of theY opening 2 is enlarged slightly as indicated by thenumeral 8, and the shaft 3 is provided with an annular groove 9 adaptedto receive a retaining ring I0. This ring is received partially in thegroove 9 and partially in the enlarged portion 3- of the opening 2whereby a longitudinal sliding movement of the shaft 3 may take placewhen it is not connected for use in order that. the brush element may beremoved therefrom, as will be presently observed.

A shieldor other suitable supporting means I I is provided at theforward end of the handle and may be integral therewith or otherwisesuitably secured. thereto. The shield` Irl extends longitudinally of thebrush element and partially surrounds it as shown. The forward end ofthe shield II has an upwardly extending end I2 having an opening at, theinner side thereof to receive a bearing member I3.

The brush spindle or shaft Ill has radially extending bristles IEthereon and is adapted to haveone end thereof received within thebearing I3, while its other end is provided with a transverse rib I6adapted to be received within a transverse slot I l in the outer end ofthe shaft 3. When the elements above described are in place as indicatedin Fig. 2 and the rear end of the shaft 3 is connected to a flexibleshaft, no longitudinal movement of the shaft 3 will be permitted, androtary movement thereof will; carry with it the brush spindle I4 and thebristles I5 extending radially therefrom. The brush element may beeasily removed for cleaning or replacement by merely sliding the shaft 3rearwardly, thus disconnecting its forward end from the brush shaft I 4.

One form of guard means which may be used to guide the lip outwardly andthus prevent the lli-p of. thevuser frornbeing drawnl inwardly bevf Iltween the shield and the brush element during rotation thereof isdisclosed in Figs. 1 to 7. In this form of the invention, a plurality ofspaced apart members I8, which may be termed teeth" for convenience, arelocated along the length of the shield II and extend inwardly betweenthe bristles I5 of the brush element. The specific form which theseteeth may preferably take may be clearly seen in Figs. 4 and 7 where itwill be noted that the inner or lower edgeof each tooth I8 is curvedupwardly and inwardly as at I9 and blends with the upper edge 2D whichis also curved upwardly and inwardly. These teeth may be located alongeither or both edges of the shield II. Ifthe brush is so designed as tohave areversing mechanism therein, thus enabling the brush to rotate ineither direction, it will then be desirable to have'the teeth located oneach side of; the brush. If, however, the brush is to be driven in onedirection only, then teeth are necessary on one side only of the shield.For example, since the brush should always, rotate in a. manner to brushtheteeth away from.. the gums, if the brush element rotates in aclockwisedirection as viewed in Fig` 4, then the teeth on the right handside thereof will be utilized to keep the lip of the user from beingdrawn between the shield and the brush element. When the brush rotatesin the opposite direction, then the teeth on the opposite side of theshield comeA into use for the same purpose.

It will be clear that the teeth disclosed herein may assume a number ofdifferent shapesand sizes other than the ones specifically shown herein.l Referring now more particularly to Figs.,8 and 9, I have disclosed amodified formof guard element in the shape of partitions. In.v this casethe shield 2 I may be of ay slightly different configuration and may notextend upwardly at each. side thereof as great a distance as the shieldshown. in Fig. 4, although this is,` more or less immaterial. This formof shield, however, is also provided with an upwardly extending end 22vin. order to support the brush element shaft in a way similar to thatdescribed above. The shield inthis case is provided with a plurality ofpartitions 23 which are spaced apart longitudinally of the shield ZIrand extend upwardly between the'bristles of the brush element. Thepartitions shown herein may be formed of solidmaterial and may be madeintegral with or secured to the'bottom of the shield 2 I. In thespecific form of partition shown herein the outer edges thereof extendupwardly as at 24` and are curved inwardly and downwardly as at 25 andterminate below the shaft I4 of the brush element. In the use ofpartitions this is necessary in order to permit removal of the brushelement.

Here again the outer curved edges of each partition acts as a guard andwill prevent the lip of the user from being drawn in between the shieldand the brush element.

Fig. 10 discloses a still further modified form of guard means and inthis case they may take the form of spikes or prongs 2.5. These prongswill preferably be integral with the shield 21 and will be spacedY apartthroughout the length thereof and will be curved inwardly as at 28, exftending between the bristles of the brush element and in this wayperform the same functions attributed to the other forms described'above.

From the foregoing description it will be evi.-

ldent that I have provided a novelv improvement in theart` of rotarytoothbrushes wherein suitable guard means are provided to prevent thelip of the user from being drawn inwardly against the brush or betweenthe shield and the brush element when such a shield is used. It will beclear that ii it is desired to omit the shield, then other means ofsecuring the guard members in place may be used. It will also be clearthat changes may .be made in the form, construction and arrangement ofparts from any of those disclosed here-in without in any way departingfrom the spirit of the invention or sacricing any of the attendentadvantages thereof, provided, however, that such changes or modicationsfall within the scope of the claims appended hereto.

Having thus described my invention what I claims as new and desire tosecure by Letters Patent of the United States is:

1. A rotary toothbrush of the class described, comprising a handleportion having a rotatable spindle extending therethrough, a brushelement connected to one end of said spindle and rotatable therewith, ashield partially surrounding said :brush element, and a plurality ofspaced guard members extending inwardly toward the spindle axis from aside of said shield between the bristles on said bnush element andterminating short of the other side of said shield, to thereby preventthe lip of the user from being drawn inwardly between the shield and thebrush element during rotation thereof.

2. A rotary toothbrush of the class described, comprising a handleportion having a rotatable spindle extending therethrough, a brushelement connected to one end of said spindle and rotatable therewith, ashield extending lengthwise of and partially surrounding said brushelement, and a plurality of teeth in the form of thin radial fins havingthe upper edges thereof extending generally radially inwardly from thesides of said shield and extending between the .bristles on said brushelement, to prevent the 9 lip of the user from being drawn inwardlybetween the shield and the brush element during rotation thereof.

8. A rotary toothbrush of the class described, comprising a handleportion having a rotation spindle extending therethrough, a brushelement connected to one end of said spindle and rotatable therewith, ashield extending lengthwise of and partially surrounding said brushelement, and a plurality of teeth in the form of thin, radial 'finshaving the upper edges thereof curved upwardly and inwardly from a side0f said shieid and extending between the bristles of said brush element,thereby to prevent the lip of the user from being drawn inwardly betweenthe shield and the brush element during rota-Y tion thereof.

DONALD P. GROVER.

REFERENCES (312532311) The following references are ei record in thefile oi this patent:

UNITED STATES PA'IENTS Number Name Date 474,325 Johnsson May 3, 1892761,952 Fredericks June 7, 1904 894,011 Kampie July 21, 1908 1,243,579Bates Oct. 16, 1917 1,583,192 Shorrock May 4, 1926 1,645,759 Kenyon Oct.18, 1927 1,822,631 Roig Sept. 8, 1931 2,801,982 Smith May 21, 19352,209,647 Elkins et al. July 30, 1940 2,832,234 Kircher Oct. 19, 19432,879,049 Tompkins June 26, 1945 2,400,723 Vrana May 21, 1946 FOREIGNPATENTS Number Country Date 676,771 France Nov. 29, 1929

